Spark-coil for ignition.



I. F. CAVANAGH.

SPARK COIL FOR IGNITION.'

APPLlcATloN man nAYal. 191s.

1,302,308, Patented Apr. 29, 1919.A

5a 22 I9 la ,7 le ao 2| I Z Br AITUINH as e .Fig-2, isa dia STATES PATENT OFFICE,

JCIIN E. CAVANAGH, 0E nEmnEmfCoNNECTICUT, AssIGNoE To THE CONNECTICUT TELEEHONE 'a ELECTRIC COMPANY, INC., 0E IIEBIDEN, CONNECTICUT, A Con- PORATION 0F CONNECTICUT.

SPARK-COIL FOB IGNITION.

Specification ofiLetters lvatent. I e Patented Apr. 29, 1919.

Aspuuon' mamy a1, 191e. serial No. 237,409.

structure is supported on and carried by the" spark plug itself.

Among the objects ofthe invention are to i secure increased electrical eiiciency and at the same time to produce a compact unit of relatively small size.

, These and other objects I have obtained by constructingl the unit with the secondary winding surrounding the magnetic core, the primary winding surrounding the secondv ary, and with a condenser surrounding the prlmary, the whole being inclosed within a magnetic -shell supported. by the spark plug.

I The vibrator is supported within the maglnetic shell at one end of be operated thereby. y

Various `other features of the invention will be made clear as the specification prothe core v.so as to ceeds, reference being had to the accom-v panying drawing forming a part'hereof and wherein I have illustrated theV invention embodied in different practical forms.

In said drawing:-" e

vFigure 1, is a verticalsectional view of the device.

of any preferredconstruction andprovided with the usual sparkv gap terminals 6 and 7.

atic. representation,-

8 designates the. magnetic shell which forms the .housing for all the coil parts and in the first-form of the device is ldirectly connected with the s of ascrew threaded )oint at 9.

ary windings 11 and 12 'respectively. Iv

In accordance with' this invention the secrk plug as by means the purpose of controlling the breakerpoints, said cap being shown for the purpose having a screw threaded connection with the 'ring 21.

lThe end of the core is shown covered by a plate 22 and this with the diaphragm y16 is shown carried by an insulating ring 23 removably seated inthe upper endof the magnetic shell and secured in place by suitable fastenings 24. This ring or base member 23 also serves in thedisclosure as a mounting for the screw ring 2'1. Suitable insulation 38 may be interposed between the diaphragm i and the spring supporting the upper reaker point.

Suitable terminals 25 and 2 6 are provided for. the primary circuit wires, oneA of said terminals (25) being connected with the primary by means of a lead 27. The other end of the primary is connected with the diatermnal 26 is connected by an external lead 29 with the timer 30. The condenser is conl nected across the breaker points by suitable vleads 31 and 32and one en of the secondary connected with the insulated terminal of the spark plug by means of a lead 33, the other end ofthe secondary having a Connection withy the primary lead as indicated at 34 in Fig.- 2. The battery, indicated at 35, is connected with the M125.

The modified form shown in Fig. 3, is

' similar to that described except that the ondary winding is applied to thefcoreland the primary A winding i's applied outside' and i magnetic shell 8' isdnot directly connected with the spark plug, it being su ported The structure describe tsin a most phragm by means of a lead 28 and the otger primary circuit termi- 1oo i the', insulating base 36 in which t ev base of the spark plug structure is mounted. -106 compactform of coll u nlt and one wherein the greatest electrical eiiciency is obtained fromboth. the primary and secondary Windings in that the primary being removed `from the core is located in a comparatively weak portion of the magnetic ield and therefore subjected to a reduced counter E. M. F., whereas the secondary being located next to the core is subjected to the maximum strength of the magnetic field. This it will be evident results in reduced sparking at the breaker points and the primary and secondary both operating at maximum efficiency serve to produce an intensified igniting spark of high eliiciency. .The location of the condenser at the outside tends to keep the capacity of the same constant in that the temperature of the same is maintained substantially constan-t and there is therefore not the variations in capacity arising from temperature changes. The vibrator while entirely housed and thoroughly protected is readily accessible for cleaning or renewal and is easily adjusted by simply turning the cover cap.

I claim:

1. In a spark plug unit, the combination with a spark plug, of a coil vcarried thereby and comprising a secondary winding, a primary winding about said secondary winding, and a condenser about said primary winding. i

2j In a spark plug unit of the character set forth in claim 1, an outer magnetic shell surrounding and inclosing the coil struc-- ture.

3. In a spark plug unit, the combination with a spark plug, of a coil carried thereby and comprising a magnetic core, a secondary Winding about said magnetic core, a primary winding about thesecondary Winding anda magnetic shell inclosing said windings and core.

4. In acombination like that set forth in claim 3, a condenser within the magnetic shell and surroundlng the primary winding.

' 5. The combination with a spark plug, of a coil unit carried thereby and comprising a magnetic core, a vibrator operated thereby, a secondary Winding on said core, a primary/ winding surrounding the secondary winding, acondenser surrounding the primary winding, and a magnetic shell surrounding the having a bearing on sa'd spring for the I,

purpose of adjusting the co/ntact points.

7. In a spark plug coil unit, a spark plug, a shell carried thereby, a magnetic core and primary and secondary windings within said shell, a diaphragm removably supported in the shell, a contact point carried thereby, a

coperating contact point and a spring supporting the same, and an adjustable cap for the shell engaging said spring Contact.

8. In a spark coil, a magnetic shell, an

annular insulating base mounted in one endA thereof, vibrator contacts carried by said base and a magnetic core and prlmary and secondary windings within the shell.

9. A spark coil comprisingya magnetic i core, la secondary winding on said core, a primary winding surrounding the secondary winding, amagnetic shell surrou-nding the primary and forming a part of the magnetic circuit, vand a condenser also 'surrounding the primary winding.

JHN F. cAvANAGH. 

